I currently like the system that we have, it is quite well known that a trainer would want to change their pokemon in the event that another pokemon was sent out after they knocked out one of the opponents. Only people who have improperly EV'd pokemon or something of that nature would complain about this...The system is functioning and great the way it is in this regard. Not being rude, just being honest.

Thereby comes that if you're using your head, you can think off a strategy.

Called: Sacrifice, if you know you're about to lose, just smashing the opposing pokémon, so that you can choose a pokémon(wich has super effective moves against the opposing opponent) and 1 shot fainting the opposing opponent.

Then don't sacrifice your pokemon, switch it, that is how you get all nice and battle perfect is learning another type of strategy. Simple as that. Instead of focusing on strategies you'd use in the game, focus on ones that would work for this game. all of us have had to adapt.